The traditional logic of preventive war is that if war is inevitable, the best time to fight is sooner rather than later, before the other side can continue to build up military strength that would prove more powerful in a future war. The U.S. attack on Iraq in 2003 follows the theory of preventive war: remove Saddam Hussein from power before he acquires enough nuclear technology in which he can support a nuclear attack on the United States. The debate on whether Iraq posed a sufficient and imminent threat to U.S. security will no doubt be continued in the foreseeable future, but the purpose of this paper is analyze to what extent is a preventive war against those that acquire weapons of mass destruction a just one? The tradition of the ‘just war’ in the West owes its earliest beginning to Thomas Aquinas, who articulated the three necessary conditions for a just war, among which he numbered “a just cause…namely, that those who are attacked, should be attacked because they deserve it on account of some fault…[such as] to make amends for the wrongs inflected…or to restore what it has seized unjustly,” and the “rightful intention.” Grotius has continued this argument by building an argument against “assumed” danger and writing that “those who accept fear of any sort as justifying anticipatory slaying are themselves greatly deceived, and deceive others.” In a more contemporary setting it has been argued that a war to preserve international order (as a war based on fears of proliferation might be characterized) – even if a preventative one – might be just because it is fought to preserve the balance of power that ensures stability and security. However, Michael Walzer has suggested that while “democratic nations” have been “less likely to fight preventative wars than dynasties are,” there is still “moral necessity” in “rejecting any attack that is merely preventative in character, that does not wait upon and respond to the willful acts of an adversary.” The threat posed by the proliferation of weapons of mass destruction among networks of terrorist cells has changed the way the White House has viewed the concept of imminence of threat since September 11th. According to the Bush administration, the concept of imminent threat must adapt to the age in which individual groups and states actively seek the world’s most destructive technologies. Where, historically, states have defended themselves against aggression considered imminent and international law has supported the notion that nations need not suffer devastation before they can take steps to defend themselves against imminent threats to national security, scholars have continued to debate whether, under article 51 of the UN Charter, a state may use force in “preemptive,” or “anticipatory,” self-defense, particularly in the context of nuclear strategy. The new doctrine of preventative war, in other words, forces us to judge whether new standards of imminence should replace traditional standards that emphasize conventional forces, troop movements and public statements. Can a preventative war be a just war and withstand the scrutiny of the political tradition of the West? Or is the pursuit of new standards a specious and dangerous departure from established principles of political order that have supported and been supported by democratic traditions? Drawing upon several authors within international relations and political theory, this study will attempt to answer those questions and chart a path forward from the war in Iraq into a future where the proliferations of weapons of mass destruction have forced the re-evaluation of these standards. [ABSTRACT FROM AUTHOR]